A recently published working paper by National Bureau of Economic Research, (May 2014) based on nationwide data, found that a 20 percent increase in school funding, due to changes that began in the 1970s, produced dramatic results in the academic success of low-income students:
?[A] 20 percent increase in per-pupil spending each year for all 12 years of public school for children from poor families leads to about 0.9 more completed years of education, 25 percent higher earnings, and a 20 percentage-point reduction in the annual incidence of adult poverty; we find no effects for children from non-poor families. The magnitudes of these effects are sufficiently large to eliminate between two-thirds and all of the gaps in these adult outcomes between those raised in poor families and those raised in non-poor families.”
My thanks to Tom Miles, Albuquerque for alerting me to this.